CN101260786A

CN101260786A - Sucker rod end fittings and method of using same

Info

Publication number: CN101260786A
Application number: CNA2008100030317A
Authority: CN
Inventors: 大拉塞尔·P·拉特利奇; 小拉塞尔·P·拉特利奇; 瑞安·B·拉特利奇
Original assignee: FIBER COMPOSITE MATERIAL CORP
Current assignee: FIBER COMPOSITE MATERIAL CORP
Priority date: 2007-03-05
Filing date: 2008-01-10
Publication date: 2008-09-10
Also published as: US8113277B2; WO2008108835A1; US20120141194A1; US20080219757A1

Abstract

An improved end fitting for sucker rods or continuous sucker rods is described herein. The end fittings are designed so as to form wedges which enhance the connectability of the end fitting to the rod, and further, the wedge or wedges approach the rod asymptotically so as to avoid any abrupt discontinuities in the wedge or wedges thus substantially eliminating stress concentration areas and potential failure areas in the rod. The improved design provides for better formed wedges having a back relief to resist compressive forces and thus provide more reliable rod to end fitting connections.

Description

Improved sucker rod end-fitting and using method thereof

Related application

The application relates to U.S. Patent application " Improved Method of Assembling SuckerRods and End Fittings ", sequence number is--, the applying date---, and relate to U.S. Patent application " Continuous Sucker Rod and Method of Using Same ", sequence number is--, the applying date---.

Technical field

The present invention relates to field produces, relate more particularly to end-fitting, this end-fitting uses with glass fiber sucker rod or synthetic sucker rod together with down-hole pump and the pump actuating system that is positioned at the surface.

Description of drawings

For further understanding characteristic of the present invention and purpose, with reference to following detailed description, similar elements is represented by same or analogous Reference numeral in the accompanying drawings with in conjunction with the accompanying drawings.

Fig. 1 illustrates the side partial cross-sectional that has the pit shaft that is connected the rod string between pump and the pump driver according to of the present invention;

Figure 1A illustrates the side partial cross-sectional that has the pit shaft of rod string according to of the present invention, and this rod string comprises the bar that is connected more than between pump and the pump driver;

Fig. 2 illustrates the flow chart of assembling sucker rods and end-fitting;

Fig. 3 illustrates the partial side view of the embodiment of sucker rod, and the graticule that is used to assemble according to of the present invention is shown;

Fig. 4 illustrates the side partial cross-sectional according to sucker rod end-fitting of the present invention;

Fig. 4 A illustrates the sectional view according to improved sucker rod end-fitting of the present invention;

Fig. 5 illustrates the side partial cross-sectional according to the part of sucker rod of the present invention;

Fig. 5 A illustrates the bottom, cross-sectional view according to sucker rod shape of the present invention;

Fig. 6 illustrates the process according to manufacturing coiled rod of the present invention in a flowchart; With

Fig. 7 illustrates the side partial cross-sectional according to the optional embodiment of the part of sucker rod of the present invention.

The specific embodiment

Thereby use sucker rod known in the art activates down-hole pump from the pit shaft recovered oil.Usually, a series of sucker rods are end to end to form rod string, and this rod string extends to pump 14 (Fig. 1) from pump driver 10.Should be appreciated that pump driver 10 is generally pump drive assembly (pumpjack) (being the beam pump system) or other known pump driver.In addition, down-hole pump 14 is generally conventional pumps known in the art.Should be appreciated that, although glass fiber or synthetic rod weight are lighter, but sucker rod is connected by metal end joint 30 usually, metal end joint 30 has increased the weight of post, and because the pump driver must overcome the weight of rod string, so metal end joint 30 is important factor at very dark pit shaft, this rod string comprises that metal end joint 30 is to activate down-hole pump 14.

Should be appreciated that rod string can be made of many bars that are about 37 feet, this post can be by comprising single continuous bar, or longly be hundreds of feet or even thousands of feet or longer a plurality of continuous bar.No matter the length of sucker rod how, and is said, preferably by 30 assemblings of the end-fitting shown in Fig. 4 or the 4A.

Fig. 1 illustrates common pumping system, and wherein pump driver 10 is common beam pump or pump drive assembly, and is connected to down-hole pump 14 by the rod string 12a that inserts pit shaft 8.Rod string 12a can comprise bar or its any combination that extends to the continuous bar of the coiled rod of pump driver 10, a series of connections, a series of conventional length that link together from down-hole pump 14.Preferably, sucker rod 12 is fiberglass pole or synthetic bar.Should be appreciated that said, when continuous sucker rod 12 was the integral stem of basic extension between pump driver 10 and following table face-pumping 14, rod string 12a can be identical with coiled rod 12.

With reference now to Fig. 2 and 3,, usually, sucker rod 12 and respective end portions joint 30 thereof are prepared individually, and fit together, and test end-fitting 30 is to the globality of the connection of bar 12.Fig. 2 illustrates the flow chart corresponding to the step of preparation and assembling end-fitting 30 and bar 12.Fig. 3 illustrates bar 12 and respective element hereinafter described.When step 100 is made end-fitting 30, in the proper mass control of each suitably error, preferably check this end-fitting 30 in step 105.Should be appreciated that suitably error refers to the manufactured particular design specification of end-fitting 30.What it is also understood that is that the quality control checking of error also can be carried out in manufacturing equipment or be undertaken by the third party examiner.If end-fitting 30 has passed through check criteria, just can advance to next step 110.Be the needs of making in the future, acceptable dimensionally end-fitting 30 can be placed in the stock.Usually, if end-fitting 30 does not pass through size and/or error-detecting, then in step 106, end-fitting 30 can return manufacturer 106, and strikes off, and repairs (promptly weld and/or process, thereby meet required size/error criterion) or its combination.Those skilled in the art will appreciate that size/error-detecting can carry out on some predetermined portions of the end-fitting that each end-fitting 30 or some statistical sampling methods are selected.

At next step 110, clean this end-fitting 30.Clean operation preferably includes at least once and cleans.But end-fitting 30 can clean with multiple conventional method and remove dust, dirty skin, oil/fat or other may rest on end-fitting 30 lip-deep pollutants.Should be appreciated that cleaning 110 also can comprise to be checked and remove making burr, borings or other foreign matter left over.What it is also understood that is that cleaning 110 can manually or automatically carry out.

Behind cleaning 110, in step 115, end-fitting 30 is placed to so that allow release agent is imported end-fitting 30.Should be appreciated that release agent can be multiple release agent commonly used.The metal material that release agent will prevent end-fitting 30 is bonding with the adhesive that is used to be connected end-fitting 30 and rod end 60.Should be appreciated that more fully that also as described below, the new method of assembling does not rely on the chemical adhesion of end-fitting 30 and bar 12 but mechanism.Therefore, the order of release agent is more clear hereinafter.

Preferably, for applying release agent, the end-fitting 30 that has cleaned is inverted, thereby release agent can be introduced into end-fitting 30.Preferably, in step 117, whole end-fitting 30 is full of release agent and is allowed to and is held.Preferably, end-fitting 30 kept about 3-4 minute.But, the retention time variable and this should not be considered as the restriction.Predictably, the automation more and advanced more technically because assembly becomes, and because different release agents is developed and tests, so the retention time can be changed into more precise time, and can incorporate other step into, such as, but be not limited to sprayed coating, hot compress, cold compress or its any combination.After the retention time, release agent is poured out from end-fitting 30.Should be appreciated that,, then pour out and/or the retention time may change or be eliminated if use the sprayed coating of some type.Should be appreciated that, after release agent is poured out, will allow end-fitting 30 to be held, thereby allow roughly all remaining release agents of drying.

After step 119 was poured out, in step 121, the end-fitting 30 of coating preferably was placed in the heating environment at the release agent that enters, and this heating environment is such as, but be not limited to baking box.Baking box can be and is used for such as discharging the conventional oven that stress or heat treated metal are handled.Preferably, end-fitting 30 still remains in the heating environment such as baking box, reaches the temperature of about 150F until it.Should be appreciated that definite temperature can be handled the definite type of suggestion, release agent owing to the curing of the manufacturer of release agent, material type or the other factors relevant with solidification process that is used to make end-fitting 30 changes.After solidifying, end-fitting 30 can be moved to land regions or stock storage area, assembles with preparation and oil pumping rod end 60.

In step 125, sucker rod 12 (end-fitting 30 is with thereon assembled) is examined after formation.Should be appreciated that the optimal way of making sucker rod 12 is by pultrusion (pulltrusion).But other manufacture method also can be expected and not be considered as qualification to it.Preferably, the underproof body of rod 12 is separated to strike off or to repair.Preferably, next procedure 130 is suitably to measure the body of rod end 60 that will hold end-fitting 30 with mark.Preferably, will with each end 60 that end-fitting 30 is assembled mutually on make two graticules.The length in the zone 66 that 62 expressions of graticule will be sanded.The appropriate location of second graticule 64 expression end-fittings 30 after on being placed in sand milling end 60, as hereinafter in detail as described in.Should be appreciated that the position of mark is the diameter of the body of rod 12 that will use and the function of end-fitting 30.The position of

mark

62,64 can or use scale to determine by measurement, thereby improves the repeatability and the accuracy of mark position.Mark 62,64 can form with various usual manners, but preferably,

mark

62,64 is on the surface of bar 12, and this mark is such as, but be not limited to paint mark or ink markings.Although slight cut mark also is acceptable,, it should be noted, do not dig out dark cut from the teeth outwards, and slight cut mark may be difficult to be recognized in other operating period.In addition, because after thermal cure step, at least one in the

graticule

62,64 must be as seen, so

mark

62,64 is necessary for the type that stands high temperature.In step 132, the qualified body of rod 12 preferably moves into sanded area.

Preferably, bar 12 is sanded at end 60 places that will receive end-fitting 30.In one embodiment, rod end 60 is sanded in machine.In another embodiment, rod end 60 is by sandblast, but In yet another embodiment, manually carries out sand milling.Should be appreciated that the step of machine sand milling is more accurate, and preferably check and execute-in-place during, the lower percent defective of acquisition after assembling rod end 60 and end-fitting 30.What it is also understood that is that the machine sand milling also can be undertaken by complete combination automatic or automatic and manual sand milling.Combination automatic and manual sand milling comprises that terminal 60 by manual sand milling around the machine of its longitudinal axis rotation body of rod 12.Preferably, assist by machine or the manual sand milling that fully manually carries out uses the sand paper of granularity 50 to carry out.But, should be appreciated that the granularity of sand paper can change.Preferably, sand milling step 132 will allow more fully being connected between adhesive and the body of rod 12.Be apparent that from foregoing description and hereinafter further detailed description the in detail adhesive must be bonding with rod end 60, but will be not bonding with end-fitting 30.

After step 132 was sanded, in step 134, sand milling end 60 preferably was cleaned 134 and carries out bonding better surface to provide at rod end 60.Preferably, with alcohol wash sand milling end 60.But, can use the cleaning agent or the chemicals of multiple routine, as long as they do not conflict mutually with the base material of the body of rod 12 or cause its damage.Endways 60 be cleaned with drying after, the body of rod 12 is preferably the step of the assembling body of rod 12 and end-fitting 30 and prepares.

Number of assembling steps 138 comprises the end-fitting 30 of filling previous preparation with the adhesive of scheduled volume.Should be appreciated that adhesive is the general type that is bonded to the material of the body of rod 12.But other adhesive also is acceptable, and the selection of special adhesive be not taken in be considered as herein the restriction.In case adhesive is placed in the end-fitting 30, end-fitting 30 just is placed on the body of rod end 60.

Preferably, end-fitting 30 manually applies and suitably is placed on the rod end 60 then by hand-operated tools.Preferably, end-fitting 30 is positioned to align to guarantee that it arrives the bottom with second graticule 64, be that rod end 60 is fully inserted in the end-fitting 30, but still between the external surface of the inner surface of end-fitting 30 and rod end, form essential cavity 24,26 (referring to Fig. 4).It has been found that if end-fitting 30 rotates on the rod end 60, adhesive just more is evenly distributed between the inner surface of the surface of rod end 60 and end-fitting 30.Preferably, assembling tool allows end-fitting 30 to locate more accurately and repeatedly in each the application.Should be appreciated that the additive method that end-fitting 30 is placed on the rod end 60 also is possible.These methods can include but not limited to use the rig commonly used of rotation at a high speed, rig such as air pressure, hydraulic pressure or wind-force, this rig uses in machine rotation body of rod 12 and the end-fitting 30 one or two, or various other devices, this device will allow end-fitting 30 suitably to locate with respect to rod end 60, keep adhesive simultaneously and distribute equably in

cavity

24,26 comprehensively,

cavity

24,26 is formed between the external surface of the inside of end-fitting 30 and rod end 60.Should be appreciated that, keep assembling at the life period of sucker rod 12, the quantity in the

cavity

24,26 of adhesive between the external surface of inside that is formed on end-fitting 30 and rod end 60 and distribute extremely important in order to make the body of rod 12 and end-fitting 30.Therefore, the mode that end-fitting 30 is placed on the rod end 60 is extremely important.Unsuitable assemble method will be placed too much adhesive, the

cavity

24,26 between the inside that promptly forces too much adhesive to leave to be formed on end-fitting 30 and the external surface of rod end 60.Space in the adhesive that the too much placement of this adhesive can cause solidifying, or lack enough cure adhesive amounts, thus damage or destroy the mechanical bond between the body of rod 12 and the end-fitting 30.What it is also understood that is, if if adhesive does not have to distribute equably or places too much adhesive and cause space or air pocket comprehensively, then may during curing produce hydraulic effect.This hydraulic effect edge promotes end-fitting 30 towards the direction of the end of sanded area 66.Should be appreciated that this phenomenon is not desirable,, thereby can cause the inspection of bar 12 defective or cause the more expensive and dangerous premature failure of on-the-spot sucker rod 12 because this will cause the inappropriate or bad assembling between the body of rod 12 and end-fitting 30.Thereby second graticule 64 also is used for any moving of vision ground inspection end-fitting 30 during cure stage.The purpose and the advantage of this mechanical bond illustrate in greater detail at this.

At end-fitting 30 after step 138 suitably is assemblied on the body of rod end 60, in step 140, end-fitting 30 and body of rod end 60 preferably heat cure to guarantee suitably bonding between the adhesive in end-fitting 30 and rod end 60.The method and apparatus that has multiple hot setting adhesive.Preferably, adhesive and rod end 60 and joint 30 are preheated together, reach the temperature of about 350F up to adhesive.Should be appreciated that, can use different heating techniques to reach this preheat temperature rapidly.A this method is to use the brigh emitter value with about 1300F temperature.The high temperature of the pipe that is connected with amphibole (flashstone) allows the adhesive temperature to reach 350F in less than 2 minutes.The rod end 60 of preheating and end-fitting 30 preferably place heating environment then, and this heating environment is such as, but not limited to the convection oven that can keep the 350F temperature.Preferably, bar 12 and end-fitting 30 assemblies were cured in heating environment one hour at least.Those skilled in the art should be appreciated that, hardening time and temperature can be according to following factors vary, and this factor is such as, but not limited to the type of validity, ambient temperature and the humidity of the size of the material of the material of the type/plate of adhesive, the body of rod 12, joint 30, bar 12, Fast Heating and the heating environment that uses.

Should be appreciated that, preferably keep following the tracks of the time and the temperature of solidification process.This can realize by different way by using complicated chart recorder or computer control, perhaps realize by manual writing time and temperature more simply.Should be appreciated that no matter the device of following the tracks of cure cycle how, bar 12 can heat or heating individually in batches.

In step 142, the body of rod 12 and the end-fitting 30 that has adhered to are removed and are checked from heating environment.As above-mentioned simply as described in, a possible defective is a hydraulic effect, air and/or moisture that this hydraulic effect causes coming and going are captured in the adhesive.This hydraulic effect will be tending towards forcing end-fitting 30 to remove from the body of rod 12.Because second graticule 64, so can promptly check end-fitting 30 by vision, to be used to representing that end-fitting 30 moves, promptly second graticule 64 is all represented moving of end-fitting 30 with any separation the between the end-fitting 30.

In step 144, bar 12 and end-fitting 30 allow to be cooled, and prepare to be used for further inspection then.

In step 147, the bar 12 of cooling carries out tension test to set the mechanical wedging (below will describe in detail) between adhesive and the end-fitting 30.Should be appreciated that tensile test is used to set up and check the integrality of the mechanical bond between the body of rod 12 and the end-fitting 30.What it is also understood that is that after curing 140 and cooling 144, end-fitting 30 will become flexible and can 60 rotations of distaff end.Thisly rotate to small part because adhesive is bonded to the body of rod 12 but not is bonded to end-fitting 30, this is because release agent puts on the inside of end-fitting 30.But because the geometry of joint 30 and the cavity of being filled by adhesive between rod end 60 and end-fitting 30 24,26, joint 30 can not leave rod end 60.Preferably, tension test is carried out under the predetermined pressure corresponding to the diameter of sucker rod 12.When exerting pressure, be bonded to the body of rod 12 but not the adhesive that is bonded to end-fitting 30 is out of shape by end-fitting 30, thereby between the end-fitting 30 and the body of rod 12, set up the wedge type mechanical bond along the direction that end-fitting 30 is removed from the body of rod 12.The remainder of tension test is the integrality of the newly-established mechanical bond of proof, thereby guarantees that bar 12 does not separate during use with end-fitting 30.Those skilled in the art will appreciate that after tension test end-fitting 30 will keep static and can not move or 60 rotations of distaff body end.

In step 150, the sucker rod 12 of assembling and end-fitting 30 visual inspections are suitably to assemble.Preferably, if end-fitting 30 by correctly bonding, then end-fitting 30 will move about 1/8th (1/8) inches along the direction (being rod end 60) of tension test.But vision ground detects this moving, because adhesive original position at end-fitting 30 when applying at first and solidifying forms " mark " 64 '.Preferably, mark 64 ' is identical with mark 64, but should be appreciated that, graticule 64 can be no longer as seen, so the mark 64 ' that adhesive forms can be next graticule.Behind the initial alignment of end-fitting 30, should when adhesive is dry in the end of end-fitting 30, form by " mark " 64 '.Therefore, when end-fitting 30 moves during tension test when forming wedge shape with the adhesive that will solidify, as seen adhesive line becomes, and in fact visual representation end-fitting 30 has moved what thereby allow easily.

Next, in step 155, the sucker rod 12 of assembling can be prepared to be used for shipment, use or storage.Should be appreciated that, can use several conventional steps, such as, but not limited to end-fitting 30 is applied the screw thread protection device, with rust protection agent coated end portions joint 30, other quality control inspection or inspection are sprayed paint, and case or store this finished product.

Should be appreciated that above-mentioned steps need not carried out with described accurate order.Some step can be carried out simultaneously, such as the preparation of end-fitting 30 and the preparation of rod end 60.Equally, inspection and number of assembling steps can carry out in the same area, and perhaps parts can be moved to the specific region to carry out particular step.What it is also understood that is can adopt multiple device to realize identical result, and not break away from spirit of the present invention described herein.

For purpose of the present disclosure, term " ripple ", " waveform ", " sine wave " or " S shape " refers to the asymptotic property of the curvature of this transition face.Can understand asymptotic curvature by distinguishing mutually with tangent line or arch curvature.If curve is prolonged fully, then tangent line or ogive curve keep and the crossing or contacted possibility of the external surface of bar 12.On the contrary, asymptotic curve is to prolong the unlimited recurrence that curve can not intersect with bar 12 in any case.Any curvature of non-asymptotic annular transition face will be set up unexpected discontinuous in the wedge shape that forms, thereby may cause the body of rod 12 is formed maximum destructive power.

Fig. 4 and 4A illustrate end-fitting 30, and this end-fitting 30 can be installed on any sucker rod, no matter whether this sucker rod is continuous, or do not have commercial lengths, or have random length between end-fitting 30 and sucker rod.Sucker rod 12 preferred insertions in the bottom end junction chamber 32.Should be appreciated that, the shape of cross section of end-fitting 30 should be substantially and the shape of cross section of sucker rod 12 be complementary.For example, but be not intended to limit, if the cross section of sucker rod 12 for circular substantially, then the shape of cross section of the bottom compartment 32 of end-fitting 30 will be for circular substantially.For another example, but be not intended to limit, if the cross section of sucker rod 12 is basic polygon, then the shape of cross section of the bottom compartment 32 of end-fitting 30 will be basic polygon.But predictably, the shape of cross section of chamber 32 is different with the shape of cross section of bar.Under the unmatched situation of most of this cross sections, the shape of cross section most probable of bottom compartment 32 is circular.What it is also understood that is, end-fitting 30 can be connected to sucker rod 12, and (if this bar is continuous sucker rod) maybe can be connected field position on spool and bar 12 is stored.As described below, preferred end-fitting 30 can use the sucker rod 12 of present description, because preferred end-fitting 30 prevents to separate and the damage of anti-stopping bar 12, rupture or break from sucker rod 12.Therefore, bar 12 and preferred end-fitting 30 have the effective impact life-span of the end-fitting that surpasses conventional sucker rod and routine thereof.

In the mechanical force on acting on bar/adhesive/metal interface, there is compressive force, such as upstroke or the compressive force during the down stroke and the negative load power of pump.Negative load power refers to the power that acts on the side relative with nip side wedge wedge.This negative load power may be caused by well internal gas pressure, Wesco pump or other factor relevant with the motion of sucker rod.Negative load can promote sucker rod downwards, thereby produces compressive force on wedge.If this compressive force enough greatly or continually, then with shear adhesion agent wedge and destroy and connect.As described here, the preferred negative loading force on the wedge is a pulling force, and wherein wedge stops bar to leave end-fitting 30 to move.Negative load can have very havoc for the wedge of existing design, thereby causes the calamitous shear fails of wedge.But in the present invention, when the impact load that produces negative load took place, wedge can absorbing load lotus power, thereby and hinder the inefficacy that connects to bar.Wedge is passed to fiberglass pole with compressive force and pulling force from steel connector or end-fitting, and vice versa.Metal end joint 30 is harder than curing adhesive, and makes the shape of curing adhesive wedge produce distortion.Basically, when structure being applied compressive force and reply locomotivity, the distortion in 30 extrusion bonded doses of the metal end joints.In theory, end-fitting 30 outwards pushes this distortion towards rod end, thereby power is passed to metal end joint 30 at least to a certain extent, to disperse destructive power best.

The axial force that puts on bar causes the distortion of bar material.This distortion is passed to the whole body of rod 12, and changes according to the size of power and the transverse cross-sectional area of bar 12.The unexpected variation of the transverse cross-sectional area of bar 12 concentrates on pressure in certain zone of bar 12.Than the body of rod 12, the wedge that sucker rod 12 connects changes the transverse cross-sectional area of bar 12 in certain the regional mode that pressure is concentrated on bar 12.The power of concentrating can surpass the structural strength of the synthetic materials of bar 12, thereby causes bar 12 to lose efficacy owing to breaking or dividing.The design of early stage bar 12 is perplexed by too early inefficacy.The failure analysis of these early stage designs has disclosed when self is in disaster, and catastrophic event seldom produces inefficacy.The generation of catastrophic failure is normally because unsuitable maintenance and unsuitable material processed operation.In addition, no matter the performance of losing efficacy how, all can and fiberglass pole 12 and metal end joint 30 between interfacing get up.Can also find, along the length at interface more fully distribute the end-fitting 30 of exerting pressure reduce aspect the inefficacy more successful.

Therefore, as shown in Figure 4, preferred sucker rod 12 connectors steadily and continuously disperse power along bar-connector interface, thereby avoid concentrated force on the bar 12 to surpass the intensity of bar 12, make connector and bar 12 collaborative combinations simultaneously, thereby avoid being pulled out.Be inserted into container 32 backs (referring to Fig. 2, step 138) at bar 12, adhesive is filled the annulus of the inner surface of interior void space of wedge or container 32.Initial flowable adhesive solidifies or hardens into and becomes solid and adhere to bar 12.This adhesive is bonded to bar 12, but is not bonded to the inside of canister 32.When the bar 12 of assembling was stretched at its connector 30 places, the solid binder wedge that is bonded to bar 12 was pressed against the complementary shape of the inside of end-fitting 30, and forces end-fitting 30 to lean against on the ring wedge of solid binder.Because metal connector and adhesive wedge push each other stoping further slip, so pressure is assigned to bar 12 self.This pressure is applied on the whole surface that the adhesive wedge contacts with the metal surface.Wedge bond end joint 30 is pulled out avoiding, and disperses destructive power equably on bar/adhesive/metal interface, thereby ideally power is guided into the end of bar 60, even introduces metal end joint 30.

The distortion of the shape of the influencing profiles adhesive material of the wedge on the inner surface of end-fitting 30.This distortion is ordered about and is passed adhesive by acting on mechanical pressure on the end-fitting 30 and stress.Especially, the shape of distortion is near the shape of wedge.If the transverse cross-sectional area flip-flop of wedge, such as the transition point from a wedge to the adjacent wedge of the next one, then Bian Xing shape will respond the shape of flip-flop, thereby make distortion present " pinnacle " shape.Concentrating by the unexpected discontinuous power that causes of wedge represented on the pinnacle.This concentrated force can surpass the strength of materials of bar 12, particularly is pushed into bar 12 places on the pinnacle at the interface at bar 12 and adhesive.The characteristic that the dynamic deficiency of stress distribution causes overcoming bar/adhesive/metal interface applies the part of load (a plurality of load) and violent stress gradient with abundant distribution, thus the integrality of forfeiture interface system.In addition, the cumulative effect of the stress gradient of repetition has been aggravated the forfeiture of integrality, thereby has quickened the corrosion of involved area.Therefore, anyly reduce to cause the trial of the destructive power of catastrophic failure must concentrate on sucker rod/adhesive/metal interface.

In the design of any end-fitting 30, adopt the principle of wedge that the extracting of fiberglass pole 12 and the distribution of the power that applies that on-the-spot use is run into are provided.Wedge is formed by the bar container with inner surface, and this inner surface is shaped as the ring that forms at least one common wedge shape between the end of inner surface of container and the bar 12 that received by container.Cambridge ring has the thin portion of annular and away from the annular thick portion of this thin portion.The example of end-fitting 30 designs comprises that 5 wedges (design the earliest) are to 1 wedge.In every kind of design, the shape of (a plurality of) wedge is by the diameter of the bag portion (container) of the diameter of sucker rod 12, end-fitting 30 and the length decision of each wedge portion.Under all scenario, the zone of the discontinuous and unexpected variation of bag portion shape causes high stress level, shown in the stress analysis of particular system.The inspection of stress distribution, or do not check, will disclose the zone of these stress high concentration by due to the discontinuous shape and size of the bag portion of end-fitting 30.These zones cause the broken China of bar/adhesive phase, thereby cause above-mentioned catastrophic failure.

In the present invention, the shape of ring wedge or a plurality of ring wedge (being formed by bar container or end-fitting 30 and the cooperation that is received in bar 12 wherein) is a waveform, and wherein thick of ring or wedge near away from encircling or the body of rod 12 of the thin portion of wedge.That is to say that the annular thick portion of ring is progressively near the end of bar 60, so as do not exist on the wedge shape or on from a wedge to next wedge unexpected discontinuous.Computer model has compared the different different joint element for bar structures that wedge meter and (has comprised metal end joint 30 or bar container, the initial flowable adhesive of fiberglass pole 12 and sclerosis), this structure comprises structure of the present invention, this computer model shows that bar of the present invention connects dispersion or guided the power that acts in the connection, particularly act on the power on the fiberglass pole 12, thereby the peak value that in the body of rod 12, does not have actually, this power.Certainly, this power does not reach destructive level on adhesive of the present invention/bar interface.To wedge meter different with other of computer mould type checking, and the present invention will act on power in the connection and guide at least in part in the metal end joint 30 self, and this is the result of uniqueness of the present invention.Computer model is more completely described among 431 B1 in U.S. Pat 6,193, and it is incorporated into as a reference at this.

The waveform transition face of this end joint 30 has been avoided curvature any unexpected discontinuous of joint 30 inner surfaces, thereby avoid mechanical force concentrations on bar 12 and cause bar 12 to lose efficacy, and in the application of power, provide sufficient wedge shape to grasp, to guarantee reliably collaborative clamping between end-fitting 30 and the adhesive wedge (a plurality of adhesive wedge).

Still with reference to Fig. 4, preferred end-fitting 30 comprises end connector 20, and this end connector 20 can be suitable for being connected to pump driver 10 or polished rod, down-hole pump 14 or heavy bar, other sucker rod or other any required connection.Therefore, should be appreciated that, be shown as and have the end of thread, also can use the connection of other form, connect, connect fast or other any method of attachment including, but not limited to internal thread although connect 20.

As shown in Figure 4, end-fitting 30 forms the axial container 32 that is defined for the end that receives sucker rod 12.Axially container 32 is limited by the

conical surface

34,44 of a series of outside convergences, and when bar 12 was in the appropriate location, the exterior cylindrical surfaces 22 of

conical surface

34,44 and bar 12 further limited around a plurality of wedge shapes of bar 12 or the

ring

24,26 of taper.End-fitting 30 comprises the outer surface 28 of the substantial cylindrical that ends at male end 20.End-fitting 30 also comprises the relative flat surfaces of a pair of diameter 48, is used to make the oilfield operations person can the standard rod tong is thereon attached, thereby each sucker rod end-fitting 30 is connected to each other and/or separates.

As mentioned above, the adhesive material that sucker rod end-fitting 30 comprises capacity is with ring type filling 24,26 fully, be used for connecting rod 12 being adhered to or otherwise interconnecting to connector members 30, this

ring

24,26 is limited by the conical surface 33,44 of the outside convergence of first connector members and the cylindrical outer surface of bar 22.When bar 12 is inserted in the container 32, this bar 12 is removed many liquid adhesives, and force this liquid adhesive to enter

ring

24,26 around bar 12, wherein this adhesive solidifies subsequently, thereby forms the wedge that the angle is arranged that is bonded to bar 12 and container

conical surface

34,44.

The adhesive material that solidifies forms the sleeve with a series of annular conical surfaces, and these a series of annular conical surfaces limit a series of ring wedges between bar 12 and container conical surface 34,44.The adhesive sleeve of this sclerosis and sucker rod 12 form bonding, and with the shearing force that opposing produces when bar 12 is exerted pressure, this shearing force can be drawn back sucker rod 12 from end-fitting 30.In addition, it is bonding and bonding with the

conical surface

34,44 of connector members that the pulling force that puts on bar 12 forces the cylindrical outer surface 28 of the ring wedge of adhesive material of curing and bar.This pressure that just makes the cener line c-c that radially inwardly guides to end-fitting 30 is pressed against the ring wedge of adhesive material on the bar 12, thereby overcomes this tension that puts on bar 12, and bar 12 is remained on appropriate location in the connector members 30.

For avoiding this pressure to cause concentrating of excessive power on the bar 12, wedge must form and make there is not unexpected variation on the transverse cross-sectional area of sleeve.Wedge is the dispersion of exerting all one's strength to the required effect of the pressure that is applied to it, rather than it is concentrated to exert all one's strength.The transverse cross-sectional area of sleeve must change as far as possible smoothly, so that pressure disperses along the end of bar 12 equably, rather than concentrates on too much on any part of bar 12.

The end-fitting 30 of sucker rod of the present invention has axial outer end 53 and the closed axial inner ends of opening 33.First annular surface or wedge 34 be near opening end 53, the second annular surfaces or wedge 44 away from opening end, and near closing end 33.The transitional surface 35 of described first annular surface 34 and second annular surface 44 is limited by the zone between the line a-a.The transitional surface 35 of container 32 forms with the shape of waveform, and this waveform has more approachingly describedly opens the outside tapering part of end 53 and more near the inside tapering part of closing end 33.Transition portion 35 is the crooked external surface with contact lever 22 in spill ground not, but progressively crooked, so that subcylindrical bar surface 22 progressively, surface 35, rather than archedly or tangentially approaching.As mentioned above, with the difference of understanding between asymptotic curvature and arch or the angential curvature.Any non-asymptotic curvature of annular transitional surface will produce unexpected discontinuous in the wedge that forms, thereby may cause producing on the body of rod 12 spike of destructive power.Therefore, for the curvature asymptotic property of transitional surface, the cross section on surface 35 is preferably S shape, sinusoidal waveform or simple waveform.

Waveform transitional surface 35 makes the transition from near-ring to ring far away mild, and has realized avoiding forming on bar 12 the required effect of peak stress.Because the distortion of the adhesive that solidifies is by the transitional surface transmission of sleeve, the waveform on surface is used to make the distortion of this adhesive material mild.Therefore, pressure never concentrates on any specified point of bar 12 and surpasses the strength of materials of bar 12 at that point.Similarly, transitional surface 19 is limited between the ring or wedge near the closing end between the line b-b 33.Transitional surface 19 is approximately waveform, and progressively near the external surface 22 of the far-end of bar 12.Surface 19 only comprises a wedge in the present invention even in one embodiment.The power that the soft contoured profile of transitional surface of the present invention acts on bar 12 makes described power be no more than the strength of materials of bar 12.The flip-flop that does not have curvature, this variation forms high stress areas in sucker rod 12, thereby may cause bar to lose efficacy.Should be appreciated that other embodiment of end-fitting 30 can comprise a ring, maybe can comprise plural ring.Under any circumstance, this should should be considered as restriction of the present invention within the scope of the invention and not.

Fig. 4 A illustrates another embodiment of the improvement design of end-fitting 30.End-fitting 30 shown in Fig. 4 A comprises two wedge zones, top area or top wedge 72 and bottom section or end wedge 74.But, should be appreciated that, can use plural wedge zone or only use a wedge zone.This improved design comprises the change that has increased the zone that adhesive fills, and changes the angle of slope of the outer wall of ring.Therefore, increase the size of wedge or a plurality of wedges, this wedge is forming when this bar is provided with the adhesive of curing by spurring after bar and joint assembling.Use data by test and actual scene, have been found that these designs change the bonding life-span that has increased bar and end-fitting, avoid the premature failure in the scene simultaneously.In improvement, any or all wedge meter and can be changed.But predictably, the stress that negative load is the highest because field trial shows is concentrated usually at top wedge 72 places, only improves this top wedge 72.

Preferably, the improvement of wedge will form back taper (back relief) on transitional surface 19.The back taper that is provided by the surface area of the increase of wedge will be used for the power that is produced by negative load as damper when downward catch bar.

Usually in the prior art, wedge wall or annular surface 70 are that the circle of about 6 inches (6 ") limits by radius.But, it has been found that, by radius being increased to about 20 inches (20 "), sufficiently increase ring 26 areas, between the installation period of bar and end-fitting so that firmer wedge to be provided.The increase of radius makes the longer and surface area of wedge increase, thereby firmer wedge is provided, and particularly in dorsal part (side of the nearly rod end 60 of the wedge joint), wherein wedge must tension ground clamping and the pressure of opposing any load lotus.In addition, the increase of radius makes provides more importantly asymptotic relation for the mild transition between the above-mentioned ring.Curve has been softened in the increase of this radius, thereby forms more asymptotic relation.In addition, because the variation of radius of circle, the diameter 76 of top wedge 72 preferably increases to about 38 inches (38 ") from about 27 inches (27 ").Should be appreciated that the diameter of top wedge 72 depends primarily on the size (diameter) of end-fitting 30.Therefore, according to the diameter that the original dimension and the end-fitting 30 of end-fitting 30 will be mounted bar 12 thereon, diameter 76 can be greater than or less than 38 inches (38 ")

Preferably, be the profile of inner room of structure end-fitting, need more accurate processing to come to provide the zone for wedge.As an example and non-limiting, preferably, at first be that locating holes are bored in chamber 32 in end-fitting.Preferably, the locating hole undersized, thus the more accurate centre bore 37 that matches with rod end 60 is provided in the end of joint 30.Should be appreciated that the appropriate location of centre bore 37 provides more symmetrical wedge at assembly process.In addition, centre bore 37 preferably drilling become so that form more straight or more parallel angle in the end of centre bore 37.These angles preferably provide the superficial area of increase in the end of centre bore 37, thereby provide better clamping zone for bar connects to end-fitting, and more accurate centering is provided between bar and end-fitting.Said, end-fitting 30 to the method for optimizing of the initial connection of bar 12 comprises end-fitting screwed on the bar, removing uncured adhesive, and makes end-fitting 30 suitably placed in the middle on bar 12.Therefore, should be appreciated that the suitable cutting of centre bore 37 is to guarantee the important step of end-fitting 30 to the suitable connection of bar 12.After suitably cutting this centre bore 37, carry out different angles and the radius of procedure of processing with cutting wedge zone.

Should be appreciated that, although the preferred tolerance of the diameter of radius of a circle and ring for just/negative 0.003 (+/-0.003), can use different tolerances according to individual preference and machine and operator's ability, and it is considered as within the scope of the invention.What also should find out is, radius size and scope are herein as example and reference, and be same, and the variation that exceeds at the radius of a circle of this examples given should not be considered as departing from instruction of the present invention.In addition, should be appreciated that end-fitting described herein can be used in combination with any sucker rod with any length, and should not be considered as limitation of the present invention.

Refer again to Fig. 1, preferably, coiled rod 12 is pliable and tough, is enough to be wrapped on the large diameter spool, so that be transported to coiled rod 12 on-the-spot to insert in the pit shaft 8 from manufacturing equipment.Should be appreciated that certain shape of cross section such as diamond or other polygon, will be convenient to make continuous bar to be wound up as tighter diameter, thereby improve the transportation and the usability of continuous bar.Those skilled in the art should be appreciated that, coiled rod 12 will reduce the overall weight of rod string, because most of metal end joints 30 are cancelled, and the processing time will be reduced, because in the time of in sucker rod 12 is reduced to pit shaft 8 or before, do not need a plurality of shorter sucker rods are connected from beginning to end.What it is also understood that is, the spool of the coiled rod 12 of winding can be unloaded at the scene inserting in the pit shaft 8, or spool can be installed on the trailer, makes coiled rod 12 to launch from the spool that is installed on the trailer, and directly inserts in the pit shaft 8.What it is contemplated that is to use several different methods to launch coiled rod 12, and bar 12 is inserted in the pit shaft.These methods were saved when connecting a plurality of sucker rod commonly used from beginning to end or when rig downtime of the costliness that rod string 12a and/or down-hole pump 14 must be consumed when pit shaft is pulled out.

Figure 1A illustrates another embodiment, and wherein coiled rod post 12a comprises more than one coiled rod 12.Preferably, the length range of each coiled rod 12 is 1500 feet to 2000 feet.But, should be appreciated that, can use longer or shorter length, and the selection of length depends on following factor, such as, but be not limited to special applications, continuously size restrictions, cost of transportation and the practicality of bar spool and well operator and/possessory preference.Coiled rod 12 preferably utilizes end-fitting described in detail herein 30 (referring to Fig. 4) to link together.Those skilled in the art will appreciate that and comprise more than one continuous bar 12 but not the rod string 12a of single continuous bar 12 will still reduce the weight of roofbolt and obtain to install faster.Even in very dark well, arrive the quantity of coiled rod 12 required between down-hole pump 14 and the pump driver 10 will be significantly less than the situation when the sucker rod commonly used that uses approximately long 37 feet long, and therefore remarkable minimizing is assembled to each bar the quantity of the required end-fitting of roofbolt 12a 30.

With reference to Fig. 1 and 1A, usually, sucker rod 12 is connected in pump driver 10 by the polished rod (not shown).Preferably, sucker rod 12 adapts with end-fitting 30 (Fig. 4), and wherein an end of end-fitting 30 is connected in sucker rod 12, and the other end is suitable for being connected in polished rod.In the downhole end of closely descending pump 14 of sucker rod 12, an end of another end-fitting 30 is connected in sucker rod 12.Second end of end-fitting 30 is preferably suitable for being connected in heavy bar (not shown).Although can use multiple end-fitting 30, preferred end-fitting 30 is shown among Fig. 4 and the 4A.Should be appreciated that, when using the sucker rod 12 of more than one coiled rod 12 or length commonly used, preferably use extra end-fitting 30 to connect the continuous end 60 of sucker rod 12, with assembling coiled rod post 12a.Preferably, if sucker rod 12 and pump 14 are connected heavy bar below, then heavy bar is used to help sucker rod 12 and pump 14 to reduce by pit shaft.Heavy bar also helps to prevent bending and the stretching rod string 12a of rod string 12a, thereby makes in the impact at place, the bottom of the post 12a impact greater than the surface.Using and being chosen in of heavy bar and polished rod is known in this field, it is not described further at this.

Fig. 7 illustrates the sectional view of an embodiment of coiled rod 12.Preferably, sucker rod 12 by along roughly longitudinally direction 16 arrange that the multiply fibre glass rovings make.But, should be appreciated that fiber roving and/or glass fiber bunch (mat) can be arranged such that fiber 16 with vertical arrangement and transversely arranged fiber 18.Vertically the fiber of arranging 16 provides main tensile strength for sucker rod 12.Transversely arranged fiber provides bigger compressive resistance for sucker rod 12.Well known in the artly be, during the pumping circulation when pump driver 10 promotes or promotes rod string 12a, sucker rod 12 will stretch, and be back to its normal position then.The stretching of bar 12 and lax make the pump stroke of down-hole pump 14 be longer than the stroke of pump driver 10.Therefore, when pump driver 10 longitudinally moved sucker rod 12 towards pump 14 or away from pump 14, vertically the fiber of arranging 16 preferably provided required intensity to keep the integrality of bar.Main pressure should be appreciated that, if along the longitudinal axis of sucker rod 12, then may not need extra transverse fiber 18.But this fiber 18 is necessary for some application, and is considered as within the scope of the invention.Should be appreciated that in whole manual, sucker rod 12 refers to the glass fiber sucker rod 12 that uses glass fiber or glass fiber bunch.But, other comprise synthetic organic and inorfil use also within the scope of the invention, and should not be considered as restriction of the present invention.

Referring now to Fig. 6, glass fiber, rove or bunch totally be expressed as 40, and preferably vertically arrange (Fig. 5), but if necessary also can be transversely arranged.Then, fiber 40 soaks in resin solution 42.Should be appreciated that roughly vertically arrange or the vertical and horizontal arrangement as fruit fiber, the method for manufacturing coiled rod 12 then described herein is roughly the same.Preferably, resin 15 is a kind of thermosetting resin, but can use other resin or adhesive.Fig. 5 illustrates the resin 15 that has occupied the space between the fiber 40.After fiber 40 soaks in resin solution 42, fiber 40 is pulled out by at least one mould 43.The fiber 40 that mould 43 preferably will soak forms required cross section.Should be appreciated that required shape of cross section can have nearly all required cross section, such as but be not limited to circle, ellipse, rectangle, square, triangle, octagon, other polygon or various other shape.But preferred shape of cross section is polygon roughly, and it is called diamond (shown in 112 among Fig. 5 A) by those skilled in the art.What it is also understood that is, mould 43 can be cold mould or can be hot-die, and wherein hot-die begins its curing during by mould 43 when shaping fiber rod 12.When bar 12 passed through mould 43 by the thermal treatment zone or curing oven 45, bar 12 was further solidified.Should be appreciated that the mould 43 and the thermal treatment zone or curing oven 45 can be two independent unit, or can be individual unit, its king-rod 12 is shaped by mould 43, and almost is cured simultaneously.

What it is also understood that is that bar 12 can be hollow.Hollow stem can be used for multiple application, include but not limited to carry cable between surface and down-hole, to transmit signal, allow to produce in the hollow core fluid to eliminate relevant issues, permission has bigger pliability (for example be wrapped on the spool, or be that post gain in weight by put into weighting material in hollow core) to pumped downhole inhibitor or other chemical substance to allow continuous bar 12.

Should be appreciated that, coiled rod 12 is not cut into about 37 feet length more commonly used, but be drawn as almost any predetermined length, such as but not limited to 10,000 foot to 15,000 feet or longer single coiled rod 12, maybe will be joined together (by end-fitting 30) 1, continuous bar 12 between 500 feet and 2,000 feet.Should be appreciated that, as mentioned above, can be drawn into the necessary longer or shorter length of special applications.

The sucker rod 12 that solidifies can be wrapped on one or more large diameter spools 50 now.Should be appreciated that the diameter of spool 50 can have following size, promptly make continuous fiber bar or synthetic bar 12 during the process that is wound to spool 50, can not damage or rupture.Therefore, the diameter of spool 50 can be wide enough so that the minimum bending radius that is no more than sucker rod during winding operation.Thereafter, the coiled rod 12 of making and twining can be transported to the scene or be stored, for using in the future.The coiled rod 12 that those skilled in the art will appreciate that synthetic or the fiberglass pole manufacturing can be manufactured to multiple length.What can expect is, coiled rod 12 can be manufactured to and be used for certain depth, or can make in advance and the person of being cut is cut into Len req, shown in the element 48 of Fig. 3.Should be appreciated that, when can not when the single spool of coiled rod 12 is transported in the locality, more than one coiled rod 12 being linked together.In this application, still suitable saving in weight of the interpolation of middle end-fitting 30 and mounting cost.What it is also understood that is, multiple different cross-sectional configurations comprises hollow core, and the rod string that comprises the more than one coiled rod that is joined together also within the scope of the invention, and should not to be considered as be restriction of the present invention.

Known in the artly be that the length of rod string 12a has obviously increased weight for the end-fitting 30 on approaching surface.Although because the conical design of end-fitting ring and the formation big weight that wedge produced within it, preferred end-fitting 30 will still be connected in rod string 12a, and not transmit destructive power to rod string 12a.Find out from aforementioned, those skilled in the art should be appreciated that, preferred end-fitting 30 allows to surpass 10,000 to 15,000 foot quite long coiled rod 12 is used to activate down-hole pump 14, and not declutcher control lever 12 and end-fitting 30, or, the power that is passed to bar from end-fitting 30 destroys owing to making bar 12.

Fig. 7 illustrates the optional embodiment of coiled rod 12, for clarity sake represents with 12b.As shown in Figure 7, coiled rod 12b is tapered to make that the external diameter of continuous bar 12b is bigger at end 22 places of approaching surface and pump driver 10, and has less external diameter at 24 places, lower end that closely descend pump 14.Known in the artly be because under pump driver 10 arrival points gross weight of the required post of pump 14, the weight that the upper end of rod string 12b usually must be bigger than following end bearing.Therefore, the coiled rod 12b with bigger upper end 22 will allow the bigger weight (therefore supporting more length) of supporting coiled rod 12b.Should be appreciated that to have different external diameters because go up oil pumping rod end 22 with lower sucker rod end 24, so embodiment shown in Figure 7 need be used for end-fitting 30a, the 30b of the different size of upper end 22 and lower end 24.What it is also understood that is, if rod string 12a comprises more than one coiled rod, then each upper and lower side 60 of each bar part can have different-diameter, but preferably, and whole pumping rod 12a will be from the end on the most approaching surface to the most closely descending the terminal tapered of pump 14.In addition, what it is contemplated that is, even comprises the rod string 12a of a plurality of independent sucker rods, such as but not limited to about 37 feet bars that a plurality of end-fittings of long usefulness link together, and can be tapered to the lower end from the upper end.In such an embodiment, each bar 12 preferably has slight tapering at least on the direction of going into the well.Therefore, each sucker rod 12 can have different slightly last diameters and following diameter.But, actual situation requires to make whole post tapered by the long part that makes post is tapered, wherein this part can comprise thousands of feet sucker rod 12, and this sucker rod 12 has certain selected diameter, and makes the lower part of sucker rod 12 posts subsequently have less slightly diameter then.

Should be appreciated that some feature and sub-portfolio have practicality, and may be utilized and not with reference to further feature and sub-portfolio.This scope by claim is contemplated, and within the scope of the claims.Can find out from foregoing description, the new combination of sucker rod 12 and end-fitting 30 is provided, and this sucker rod 12 comprises coiled rod, and this end-fitting 30 stops the sucker rod 12 that breaks away from and be used to have enough diameters, if this sucker rod 12 is continuous, then there is not joint.In addition, the improvement design of end-fitting 30 and the method for preparation and assembling bar 12 and end-fitting 30 are provided.Although described and disclose specific example, the application's invention is considered to comprise and is intended to comprise any equivalent configurations, and available different ways structure, thereby with aforesaid usual way operation and operation.Therefore, it should be noted that embodiment described in detail herein for illustrative purposes can carry out the multiple modification of structure, design, application and method certainly.Because multiple variation can realize in the scope of the inventive principle of being instructed with different embodiment, and because can technical descriptive requirement carry out multiple improvement to embodiment described in detail herein, will be appreciated that details herein is interpreted as exemplary but not determinate.

Claims

1. an improved sucker rod is constructed, and comprising:

End-fitting with bar container;

This bar container has inwall, central longitudinal axis, closed axial inner ends and the axial outer end of opening, wherein said bar container comprises the ring of a plurality of whole formation, outside convergence, axially-aligned, each ring is progressively near described central axis, and towards described open the end tapered to have the diameter that reduces, this bar container limits independent transitional surface between every pair of adjacent ring, wherein each described table of crossing crosses face and comprises the continuous action surface with unexpected variation curvature;

Bar, this bar has the end that has external surface, this bar is housed inside in the described bar container by described outer end of opening, and cooperates mutually to limit doughnut between the ring of the described outside convergence of the described external surface of the described end of described bar and described bar container with described bar container;

Each described ring is limited at least one side by described inwall; And

In the described ring at least one has back taper near the axial end of described closure, wherein said back taper absorbs the pressure that negative load produced by described end-fitting and/or described bar.

2. sucker rod as claimed in claim 1 structure, at least one that comprises also that at least a portion of described inwall, this part had in the described ring of the radius of curvature between 5 inches to 21 inches limits.

3. sucker rod as claimed in claim 1 structure also is included in described closing end and away from the transitional surface between the maximum gauge of the described described ring of opening end, wherein said transitional surface comprises wave-shaped cross-section.

4. sucker rod structure as claimed in claim 1 also comprises:

Cylindrical bar, this cylindrical bar has the end that has cylindrical outer surface, this bar is housed inside in the described bar container by described outer end of opening, and cooperates mutually to limit doughnut between the ring of the described outside convergence of the described external surface of the described end of described bar and described bar container with described bar container.

5. sucker rod structure as claimed in claim 4, wherein said cylindrical bar comprises glass fiber.

6. sucker rod structure as claimed in claim 4, wherein said cylindrical bar comprises synthetic materials.

7. sucker rod structure as claimed in claim 1 also comprises:

Initial flowable adhesive body, this adhesive body is cured as the described external surface in conjunction with the described end of described bar, and is solidified as a plurality of wedges of formation to cooperate mutually with described ring.

8. sucker rod structure as claimed in claim 1, wherein said bar and/or end outer surface have roughly polygonal cross-sectional configurations.

9. sucker rod structure as claimed in claim 8, wherein said bar comprises glass fiber.

10. sucker rod structure as claimed in claim 8, wherein said bar comprises synthetic materials.

11. a sucker rod end-fitting comprises:

The bar container, this bar container has central longitudinal axis and is defined for the inwall of the ring that holds sucker rod, described inwall has axially inwardly the second portion can coalescence outwards assembled away from the first of described central axis, towards described central axis, axially inwardly can coalescence outwards assembles and progressively near described central axis and end at the 4th part of annular base away from the third part of described central axis and towards described central axis, the ring of described qualification provides wedge, and this wedge has the trailing edge that is used to distribute the leading edge of positive force and is used to distribute negative force; And

In the described part at least one has the radius of curvature between 5 inches to 21 inches.

12. the method for assembling sucker rods body and end-fitting comprises the steps:

At least one end-fitting is provided, this end-fitting has central longitudinal axis, closed axial inner ends, the axial outer end of opening, with the inwall that is defined for the ring that holds sucker rod, described inwall has the first of axially inside meeting coalescence away from described central axis, towards the outside second portion of assembling of described central axis, axially inside meeting coalescence is away from the third part of described central axis, and outwards assemble and progressively near described central axis and end at the 4th part of annular base towards described central axis, the ring of described qualification provides wedge, and this wedge has the trailing edge that is used to distribute the leading edge of positive force and is used to distribute negative force;

Oil pumping with first end, second end and external surface body of rod is provided, and wherein said first end and/or second end are constructed to match with described end-fitting;

Cut centre bore near the axial inner ends of described closure, wherein said cutting forms the centre bore of circular;

Adhesive is put on the inner surface of described end-fitting;

The described body of rod is inserted the described end-fitting that is filled with adhesive, thereby described end-fitting is installed on the described body of rod;

With described body of rod centering in described end-fitting; Wherein said centering is guided by described centre bore; And

The body of rod with end-fitting is heat-treated, and wherein said heat treatment is bonded to the described body of rod with adhesive.

13. method as claimed in claim 12, wherein said at least one end-fitting comprises the bar container, this bar container has closed axial inner ends and the axial outer end of opening, and ring with a plurality of whole formation, outside convergence, axially-aligned, described ring is progressively near described bar, and towards described open the end tapered to have the diameter that reduces, this bar container limits transitional surface at described ring and described opening between the end, wherein said transitional surface comprises the continuous action surface with unexpected variation curvature.

14. method as claimed in claim 12, wherein said at least one end-fitting comprises the bar container, this bar container has closed axial inner ends and the axial outer end of opening, and ring with a plurality of whole formation, outside convergence, axially-aligned, and wherein each described ring is progressively near described bar, and towards described open the end tapered to have the diameter that reduces, limit independent transitional surface between the adjacent ring of this bar container in being included in described a plurality of ring, each described transitional surface comprises the continuous action surface with unexpected variation curvature.

15. method as claimed in claim 12, wherein said wedge is made of the adhesive at described heat treatment curing during.

16. method as claimed in claim 15 also comprises the steps, after heat treatment, spurs the described body of rod with the direction away from described end-fitting that is:, thereby forms the described wedge of cure adhesive in described ring.

17. method as claimed in claim 12, at least one in the wherein said part has the radius of curvature between 5 inches to 21 inches.